As the dimensions of integrated circuit components decrease, more elements are put in a given area of a semiconductor integrated circuit. Accordingly, lithography processes have become more and more challenging to transfer even smaller features (e.g., less than 64 nm) onto a substrate precisely and accurately without damage. In order to transfer precise and accurate features onto a substrate, a desired high resolution lithography process requires having a suitable light source that may provide radiation at a desired wavelength range for exposure. Furthermore, the lithography process requires transferring features onto a photoresist layer with minimum photoresist line width roughness (LWR) and acceptable critical dimension uniformity. A defect-free photomask is required to transfer desired features onto the photoresist layer.
Accordingly, the inventors have provided improved methods for reducing the line width roughness and/or critical dimension nonuniformity on a patterned photoresist layer.